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Full text of "The manufacture and properties of iron and steel"

THE BASIC OPEtf-HEARTH PROCESS.
2.61
curate quantitative calculations, but otherwise the action is of little importance, since it cannot be relied on for purification of the metal., This volatilization occurs in greater measure in the.case.of sulphur, but here, also, it is impracticable to eliminate any appreciable' proportion by this method alone, since volatilization occurs only from the slag, and the action, therefore, presupposes the transfer of sulphur from the metal to the cinder, and this in turn presupposes a condition which will purify  the metal without the ex post facto intervention, of volatilization.
Sulphur can be removed in at least four ways:
(!) By metallic manganese and liquation of sulphide of manganese. The extent of this reaction is uncertain, but usually the addition of 0.60 to 0.75 per cent, of manganese reduces the sulphur content about 0.01 per cent..
(f2) By manganese ore, which,, being reduced by the metalloids of the bath, furnishes.metallic manganese.. The ore should be added with the original charge, in order that it may be thoroughly mixed with .the metal.. It is difficult to isolate the effect of this agent from the; action of the basic slag with which it must be associated, but there is no doubt that it aids in the purification.
(3) By a very limey cinder. In a former paper* I gave the results of experiments in removing sulphur by ordinary lime slags.
"'                           TABLE XI-H.
Basic Open-Hearth Slags after Melting.
		Sulphur					
Charge	Initial sulphur,	in metal after	Composition of slag after melting, per cent.				
Number.	per cent.	melting,					
		per cent.	S.	SiOa.	FeO.	CaO.	MnO.
1546	.48	.28	.28	87.58	10.26	84.53	4.66
1611	.20	.,14	.26	82.63	10.17	86.25	und.
1608	.28	.17	.22	81.80	10.98	41.45	und.
1628	.20	.16	.21	83.20	9.45	und.	und.
1648	.20	.14	.21	84.87	6.57	und.	und.
  1567	.28	.18	.20	'    80.26	10.08	45.26	6.42
1646	.20	.15	.18	88.97	11.61	und.	und.
1626	.20,	.11	.18	86.48	5.04	und.	und.
1   1564	.28	.10	.17	82.45	9.86	45.05	5.49
1555	.28	.22	.14	80.63	13.41	89.17	7.15
1680	.20	.09	.14	25.57	8.01	und.	und.
1606	.28	.19	.12	85.79	18.00	83.13	und.
1569	.28	.19	.08	84.05	18.'45	85.09	6.25
The cinder, during melting, was kept high in silica to economize lime, and part of this slag was removed after fusion, and fresh lime
* The Open-Hearth Process.   Trans. A. I. M. E., Vol. XXII, p. 446.